Anesthetic mouth rinses on the market typically contain a short chain monohydric alcohol which not only functions as an excellent solvent for the mouth rinse but kills bacteria in the mouth. For example, U.S. Pat. No. 5,270,031 discloses a mouthrinse containing ethyl alcohol and a copolymer of methyl vinyl ether and maleic anhydride. U.S. Pat. No. 5,120,528 disclose a mouthrinse containing ethyl alcohol, glycerine and water. The disadvantages associated with the use of such monohydric alcohols, however, is that they cause burning or stinging effects in the mouth of the user, and may make the mouth more susceptible to cancer. Moreover, the burning or stinging effects are amplified in formulations containing anesthetics which are chemical compounds that induce loss of sensation in the mouth prior to dental procedures. Therefore, it would be advantageous to develop an anesthetic and antiseptic mouth rinse which does not contain monohydric alcohols and eliminates or diminishes the burning sensation that previous formulations exhibit.
The present inventors have unexpectedly determined that an anesthetic and antiseptic mouth rinse may be prepared using polyethylene glycol having a number average molecular weight of 200 to 300 which does not cause a burning sensation in the mouth of the user. The mouth rinse is freeze-thaw stable and is compatible with local anesthetics and other ingredients commonly used in mouth rinses.